Environment Pollution – Water Pollutants

Water Pollutants

Sources – community waste water, Industrial waste, Agricultural chemicals waste, Thermal & nuclear pollution, Oil spills, Radioactive dump waste, Groundwater seepage etc.

• Sudden rise in water temperature due to thermal pollution, which uses water as coolant & releases hot water to source, kills aquatic animals as they have a very narrow tolerance limit with respect to temperature
• Polluted water reduces dissolved oxygen which leads to depletion of aquatic flora & fauna

• Oil spills in water can be cleaned with the help of Bregoli – a byproduct of paper industry
• Water hyacinth (an aquatic weed) can purify water by taking some toxic materials & a number of heavy metals from water.

Biochemical oxygen demand

• amount of dissolved oxygen needed by bacteria in decomposing the organic waste present in water.
• Actually, a measurement of pollution by organic wastes expressed as milligram of oxygen / liter water.

Higher value of BOD indicates low dissolved oxygen in water (BOD is only limited to biodegradable materials only)

Chemical oxygen demand

• a measure of oxygen equivalent required for oxidation of total organic matter i.e. degradable & non degradable, present in water.

Diseases by Water Pollution

Minamata

• A crippling deformity caused by methyl mercury poisoning mainly by industrial waste water
• first described in the inhabitants of Minamata Bay, Japan and resulted from their eating fish contaminated with mercury industrial waste

itai itai

• Also known as ouch ouch disease (pain in bones & joints) caused by water contamination by cadmium

Blue Baby Syndrome

• Excess nitrates in drinking water reacts with hemoglobin to form nonfunctional methaemoglobin which impairs oxygen transport

Skeletal Fluorosis

• Excess of fluorides in drinking water can cause neuromuscular disorders, teeth deformity, and hardening of bones, painful joints & outward bending of legs from knees – Knock knee syndrome

Black foot disease

• Caused by leaching of arsenic from soil & rocks to ground water used for drinking purposes

Water contaminated with lead

• Cause anemia, loss of muscle power & bluish lines around the gums

Iodine 131

• Produced by nuclear tests, passed to vegetation & then appears in milk of the cattle that consume the contaminated vegetation & is passed to humans.
• causes serious damage to thyroid glands especially among children

Sick building syndrome (SBS)

• a situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified
• causes are frequently pinned down to flaws in the heating, ventilation & air conditioning (HVAC) systems

Pollution in Leather Industry

• Leather industry in India has become 0 discharge industry as ~80% of the effluents are treated and recycled back into use and remaining 20% are solidified and their salts used for other purposes.
• As a result, Indian leather industry is REACH compliant (EU norms) and exported $4.5 bio in 2011-12 and the target is $14 bio by 2015-16 (growth rate of 20% p.a.)